Safety crank handle for autos



June 30, 1925. 1,54%4175 J. PETERSEN SAFETY CRANK HANDLE FOR AUTOS Filed June 16, 1924 ,zldwnes Z7 Patented June 30, 1925.

UNITED STATES JOHANNES P TERSEN, or AALBORG, DENMARK.

SAFETY CRANK HANDLE FOR AUTOS.

Application filed June 16, 1924. Serial No. 720,388.

2 To all whom it may concern:

' arrow in Fig. 2,

Be it known that I, J OHANNES PETERSEN, subject of the King of Denmark, residing at Aalborg, Denmark, have invented certain new and useful Improvements in Safety Crank Handles for Autos, of which the following is a specification.

In starting automobile and other motors, there is the danger that the motor may make a wrenching turn in the opposite direction, which causes the person starting it to run the risk of having his arm injured. The present invention, therefore, resides in the provision of an improved starting crank, by means of which this drawback is done away with.

An embodiment of the invention is illustrated in the accompanying drawing, in which:

Figure 1 is a side View of the improved crank-handle Fig. 2 is a front view thereof;

Fig.3 is a fragmental detail View, partly in section on line a-a, Fig. 1;

Fig. 1 is a section on line b-?), Fig. 1.

The arm of the crank-handle consists of two parts, 1 and 2 which are pivotally connected by a bolt 3, the part 2 being rigidly secured to the motor shaft 13. Normally these two parts, however, form a rigid connection, as a case 4 embraces the part 2 as well as the lower end of part 1 and thus covers the overlapping portions thereof. The case 4 is fastened to a rod 5, the lower end of which is formed into a ring which fits loosely around an eccentric 6, fastened by a screw to a ratchet wheel 7. A pawl 8 engages said ratchet wheel, and is pivoted to an arm 9 provided with a slot 10 to slidably receive a pin 11 secured laterally to the front face of the radiator, the edge of which is indicated by the dotted line 12 in Fig. 1.

To start the motor, the crank-handle 1, 2 is turned in the direction indicated by the whereby the eccentric and the ratchet wheel 7 are also rotated, so that only the arm 9 and the pawl 8 remain stationary. If now the motor should backfire, the motor shaft and the crank-handle will be turned in the opposite direction; but during this backward movement, the ratchet wheel 7 and the eccentric 6 do not rotate because of their being loosely mounted on the shaft, and because the pawl 8 prevents the ratchet wheel from turning. Owing to this fact, the ring or eccentric strap at the foot of the rod 5 will be forced to turn on the eccentric 6; and as soon as the crank has moved slightly backward the ring will have turned to such an extent on the eccentric that the case 4, which is rigidly connected to the rod 5, is drawn far enough downward on the crank to completely release the end of part 1 of the crank, which part can then turn or rock about the pivot bolt 3, so that the person operating the crank can then remove his hand therefrom.

I claim as my invention:

1. A safety crank for automobile engines and the like, comprising an arm embodying inner and outer members normally disposed substantially in line and having their inner ends overlapped and pivoted together, the inner member adapted to be secured at its outer end to the engine shaft; a sleeve slidably related to said members and normally fitting around their overlapping ends to hold them rigidly connected; and means on said shaft connected with said sleeve for automatically shifting the latter, when the engine baclcfires, in a direction to uncover said overlapping ends and thereby enable swinging movement of the outer member out of line with and relatively to the inner member.

2. A safety crank for automobile engines and the like, comprising an arm embodying inner and outer members normally disposed substantially in line and having their inner ends overlapped and pivoted together, the inner member adapted to be secured at its outer end to the engine shaft; a sleeve slidably related to said members and normally fitting around their overlapping ends to hold them rigidly connected; an eccentric on the engine shaft; and a ring encircling the eccentric and to which said sleeve is attached, said ring and eccentric coacting automatically, when a back-fire occurs, to shift the sleeve in a direction to uncover said overlapping ends and thereby enable swinging movement of the outer member out of line with and relatively to the inner member.

In testimony whereof I affix my signature.

JOHANNES PETERSEN. 

